The Eastern Cooperative Oncology Group (ECOG) membership of the University of Rochester Medical School is committed to integrated clinical trials involving the services of chemotherapy, radiation therapy, hormonotherapy, immunotherapy and surgical therapy for the care and treatment of cancer patients. The membership consists of five city hospitals (Strong Memorial Hospital, Highland Hospital, Genesee Hospital, Rochester General Hospital, St. Mary's Hospital), a surgical oncology unit in Syracuse, New York, a medical oncology unit at the Veterans Administration Hospital, Batavia, New York, and a medical oncology unit in Tompkin's County Hospital, Ithaca, New York. The component units support the protocol activities of cooperative group studies of the ECOG, Radiation Therapy Oncology Group (RTOG), Gynecologic Oncology Group (GOG), and the National Surgical Adjuvant Breast Project (NSABP). Several of the unit members also serve on disease-oriented and steering committees that are vital to executing the many varied functions of the Eastern Cooperative Oncology Group. In addition to the multidisciplinary participation in clinical investigations, this ECOG program also serves as an important teaching and training aid for medical, radiation and surgical oncologists at the University of Rochester School of Medicine.